In recent years, a type of an image display device including a television receiver has been shifted from a conventional CRT display device to a thin display device using a thin display element such as a liquid crystal panel and a plasma display. A liquid crystal panel used as a display element does not emit light, and thus a backlight device is required as a separate lighting device. A backlight device disclosed in Patent Document 1 has been known. The backlight device disclosed in Patent Document 1 includes a light source unit including an elongated base board and a plurality of LEDs (light sources) that are linearly arranged on the base board. A plurality of the light source units are arranged to achieve two-dimensional arrangement of the light sources.
Patent Document 1: Japanese Unexamined Patent Publication No. 2007-317423